The present invention pertains to exercise equipment and particularly to exercise equipment for muscles of the arms, shoulders, and back of the user.
In the field of body exercise and strength training, there is a need to exercise the upper body and arms under a resistive load. Various devices have been developed to provide a resistive force to the user as the user moves his or her arms from a position with the arms extended above the head to a position with the hands positioned below the shoulders. In such equipment, the resistance is routinely provided by an arrangement of cables and pulleys which vertically lift a stack of weights as the handles of the device are brought downward. In such devices, the resistance provided by the machine remains constant, regardless whether the user has the arms and shoulders in a relatively stronger or weaker position.
In other devices, free weights mount to lever arms at a relatively high position, requiring an attendant or the user to lift free weights high in the air to mount them to the apparatus. As the user pulls down on levers, the resistance provided by the weights varies little if any as the arms are moved from an overhead position to a position in front of the chest.
In other devices, elaborate counterbalance features are required in order to make the apparatus useful to those users with lesser upper body strength due to the weight of the weight bearing structure even when not loaded.
A need exists for an easily used, safe, pull-over exercise machine which can be used by persons of various strengths and sizes and which varies the resistive load to the muscles of the arms, shoulders and back as muscle strength and leverage decline, thereby improving exercise of the muscles over a range of motion of the arms.